summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-twl-led.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pwm/pwm-twl-led.c')
-rw-r--r--drivers/pwm/pwm-twl-led.c344
1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-twl-led.c b/drivers/pwm/pwm-twl-led.c
new file mode 100644
index 000000000000..9dfa0f3eca30
--- /dev/null
+++ b/drivers/pwm/pwm-twl-led.c
@@ -0,0 +1,344 @@
+/*
+ * Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
+ *
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
+ *
+ * This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
+ * Hemanth V <hemanthv@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/i2c/twl.h>
+#include <linux/slab.h>
+
+/*
+ * This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
+ * To generate the signal on TWL4030:
+ * - LEDA uses PWMA
+ * - LEDB uses PWMB
+ * TWL6030 has one LED pin with dedicated LEDPWM
+ */
+
+#define TWL4030_LED_MAX 0x7f
+#define TWL6030_LED_MAX 0xff
+
+/* Registers, bits and macro for TWL4030 */
+#define TWL4030_LEDEN_REG 0x00
+#define TWL4030_PWMA_REG 0x01
+
+#define TWL4030_LEDXON (1 << 0)
+#define TWL4030_LEDXPWM (1 << 4)
+#define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)
+#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))
+
+/* Register, bits and macro for TWL6030 */
+#define TWL6030_LED_PWM_CTRL1 0xf4
+#define TWL6030_LED_PWM_CTRL2 0xf5
+
+#define TWL6040_LED_MODE_HW 0x00
+#define TWL6040_LED_MODE_ON 0x01
+#define TWL6040_LED_MODE_OFF 0x02
+#define TWL6040_LED_MODE_MASK 0x03
+
+struct twl_pwmled_chip {
+ struct pwm_chip chip;
+ struct mutex mutex;
+};
+
+static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
+{
+ return container_of(chip, struct twl_pwmled_chip, chip);
+}
+
+static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
+ u8 pwm_config[2] = { 1, 0 };
+ int base, ret;
+
+ /*
+ * To configure the duty period:
+ * On-cycle is set to 1 (the minimum allowed value)
+ * The off time of 0 is not configurable, so the mapping is:
+ * 0 -> off cycle = 2,
+ * 1 -> off cycle = 2,
+ * 2 -> off cycle = 3,
+ * 126 - > off cycle 127,
+ * 127 - > off cycle 1
+ * When on cycle == off cycle the PWM will be always on
+ */
+ if (duty_cycle == 1)
+ duty_cycle = 2;
+ else if (duty_cycle > TWL4030_LED_MAX)
+ duty_cycle = 1;
+
+ base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
+
+ pwm_config[1] = duty_cycle;
+
+ ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
+
+ return ret;
+}
+
+static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
+ goto out;
+ }
+
+ val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
+
+ ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl4030_pwmled_disable(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
+
+ ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
+ u8 on_time;
+ int ret;
+
+ on_time = duty_cycle & 0xff;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
+ TWL6030_LED_PWM_CTRL1);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
+
+ return ret;
+}
+
+static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_ON;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl6030_pwmled_disable(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_OFF;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_OFF;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+ return ret;
+}
+
+static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct twl_pwmled_chip *twl = to_twl(chip);
+ int ret;
+ u8 val;
+
+ mutex_lock(&twl->mutex);
+ ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0) {
+ dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
+ pwm->label);
+ goto out;
+ }
+
+ val &= ~TWL6040_LED_MODE_MASK;
+ val |= TWL6040_LED_MODE_HW;
+
+ ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
+ if (ret < 0)
+ dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
+
+out:
+ mutex_unlock(&twl->mutex);
+}
+
+static const struct pwm_ops twl4030_pwmled_ops = {
+ .enable = twl4030_pwmled_enable,
+ .disable = twl4030_pwmled_disable,
+ .config = twl4030_pwmled_config,
+};
+
+static const struct pwm_ops twl6030_pwmled_ops = {
+ .enable = twl6030_pwmled_enable,
+ .disable = twl6030_pwmled_disable,
+ .config = twl6030_pwmled_config,
+ .request = twl6030_pwmled_request,
+ .free = twl6030_pwmled_free,
+};
+
+static int twl_pwmled_probe(struct platform_device *pdev)
+{
+ struct twl_pwmled_chip *twl;
+ int ret;
+
+ twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
+ if (!twl)
+ return -ENOMEM;
+
+ if (twl_class_is_4030()) {
+ twl->chip.ops = &twl4030_pwmled_ops;
+ twl->chip.npwm = 2;
+ } else {
+ twl->chip.ops = &twl6030_pwmled_ops;
+ twl->chip.npwm = 1;
+ }
+
+ twl->chip.dev = &pdev->dev;
+ twl->chip.base = -1;
+
+ mutex_init(&twl->mutex);
+
+ ret = pwmchip_add(&twl->chip);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, twl);
+
+ return 0;
+}
+
+static int twl_pwmled_remove(struct platform_device *pdev)
+{
+ struct twl_pwmled_chip *twl = platform_get_drvdata(pdev);
+
+ return pwmchip_remove(&twl->chip);
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id twl_pwmled_of_match[] = {
+ { .compatible = "ti,twl4030-pwmled" },
+ { .compatible = "ti,twl6030-pwmled" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
+#endif
+
+static struct platform_driver twl_pwmled_driver = {
+ .driver = {
+ .name = "twl-pwmled",
+ .of_match_table = of_match_ptr(twl_pwmled_of_match),
+ },
+ .probe = twl_pwmled_probe,
+ .remove = twl_pwmled_remove,
+};
+module_platform_driver(twl_pwmled_driver);
+
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
+MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
+MODULE_ALIAS("platform:twl-pwmled");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 08:48:52 +0000